Lined containers



April 16, 1968 L. T. NELSON LINED CONTAINERS 4 Sheets-Sheet 1 Filed June8, 1965 LAURENCE ZMszsau INVENTOR- April 16, 1968 l .T.NELSON 3,

LINED CONTAINERS Filed June 8, 1965 4 Sheets-Sheet 2 lAl/eavceZ'A/asolvINVENTOR.

4 Sheets-Sheet AGENT April 16, 1968 L. T. NELSON LINED CONTAINERS FiledJune 8,

April 1968 L. T. NELSON 3,377,766

LINED CONTAINERS Filed June s, 1965 4 Sheets$heet 4 TEAPPED/ 24 4/2 OUTLAURENCE T/VELSON INVENTOR.

BY WA United States Patent Oflice 3,377,766 Patented Apr. 16, 19683,377,766 LINED CONTAINERS Laurence T. Nelson, Danville, CaliL, assignorto Strect'on Industries Incorporated, Millbrae, Calif. Filed June 8,1%5, Ser. No. 462,211 8 Claims. (Cl. 53-27) ABSTRACT OF THE DISCLOSURE Aclosed substantially permanent container such as a metallic drum,storage tank, etc., of the type employed for the bulk storage andshipment of petroleum, chemical, and food products, or the like, whichis characterized by an interiorly disposed plastic film disposable linerto facilitate extended reuse of the container with the same or otherproducts without contamination and/ or leakage. A method is dis-closedfor the introduction of a liner to, and its removal from the interior ofa closed container through a limited access opening thereof.

This invention relates to closed drums, tanks, and equivalent closedcontainers, and is more particularly directed to closed containers ofthis type having an interior plastic liner and to a method of disposingthe liner Within the container for filling of the resulting linedcontainer with a product.

Considerable difficulties are encountered with containers such as drums,tanks, and the like, from the standpoint of leakage and contamination ofthe product contained therein. For example, it is not uncommon for drumsof the type employed for the storage and shipment of petroleum,chemical, and food products, or the like, to initially have, orsubsequently develop, cracks which result in the leakage of the product.Whats more, the container material frequently contaminates the contents.As an example, the interior walls of steel drums often rust, and therust flakes off and mixes with the oil or other contained product.Furthermore, drums and similar containers are generally not reusable.The remnants of previous contents in many instances will contaminateanother product when the container is resued. Larger containers, such asstorage tanks, suffer from many of the same disadvantages.

Various measures have been taken heretofore to overcome the above-notedshortcomings, but without any substantial degree of success. Attemptshave been made to spray or otherwise cover the container interior with aprotective coating to prevent contact between the material of thecontainer and the contents. However, the coating is susceptible tochipping such that particles of the coating may contaminate thecontained product. The coating also cracks when the drum material cracksand is thus ineffective to prevent leakage. The coating does nothing torender the container reusable.

The ideal solution to the problem is to provide .a liner of plasticfilm, or similar inert material, within the container, the walls of thecontainer backing the liner and providing the strength for supportingthe contents. This expedient has proven successful with open toppedcontainers, removable top containers, and containers which may be placedabout the liner during fabrication. However, with closed drums andsimilar containers which are provided with integral heads or other endclosures, the use of liners has been heretofore precluded for lack of away of disposing a liner within the closed container for filling with aproduct.

It is therefore an object of the present invention to provide interiorlylined closed containers.

Another object of the invention is the provision of a drum with integralheads having a disposable plastic film liner or bag therein containingthe drum contents.

Still another object of the invention is the provision of a lined closedcontainer of the class described which is effective in preventingcontamination of a contained product and leakage of the product throughcracks, and the like, which may exist in the container walls.

It is yet another object of the invention to provide a closed containerof the class described wherein the liner is disposable and may bereplaced by a new liner, thus facilitating reuse of the container.

A very important object of the invention is to provide a method ofintroducing a plastic filrn liner into a closed container .and intocontact with the walls thereof such that the resulting lined containermay be filled with a product.

It is a further object of the invention to provide a liner in a formwhich may be readily inserted into a drum through the large bung holethereof and thereafter readily inflated into contact with the druminterior.

Further objects and advantages of the invention will become apparentupon consideration of the following detailed description thereof inconjunction with the accompanying drawings, wherein:

FIGURE 1 is a sectional view taken in a diametric plane through a linedclosed drum in accordance with the invention;

FIGURE 2 is a fragmentary sectional view similar to FIGURE 1, butillustrating a conventional pouring spout cooperating with the bung holeand liner to facilitate pouring of the contents of the drum;

FIGURE 3 is an elevation view of a plastic film liner folded tofacilitate disposition in a closed drum or other closed container inaccordance with the method of the present invention;

FIGURE 4 is a view similar to FIGURE 3, but illustrating a modificationof the liner in the form of a package;

FIGURE 5 is a perspective view of the packaged liner of FIGURE 4,illustrating further details thereof;

FIGURE 6 is .a perspective view illustrating insertion of the foldedliner into a closed drum through the large bung hole thereof;

FIGURE 7 is a side elevation with portions brokenaway, of the linerinserted into the drum, and illustrating the initial stages of inflationof the liner in accordance with the method;

FIGURE 8 is a side elevation view with portions broken-away,illustrating later stages of liner inflation;

FIGURE 9 is a view similar to FIGURE 8, but with the liner fullyinflated within the drum and being filled with a product;

FIGURE 10 is a fragmentary sectional view of the upper portion of FIGURE-9, illustrating the lined drum filled with a product and the lineropening sealed;

FIGURE 11 is an elev'ational view of a drum with portions broken-away,illustrating a modification of the method;

FIGURE 12 is a view similar to FIGURE 11, further illustrating themodification of the method; and

FIGURE 13 is a side elevation view with portions broken-away of a lineddrum, and illustrating a preferred method of removing the liner from thedrum for subsequent replacement with a new liner.

Briefly stated, the present invention provides a closed container havingan interiorly disposed plastic film liner in contact with the containerwalls, so as to be rigidly supported thereby. In this regard, the termclosed container is to be taken as including closed drums as well aslarger vessels, such as tanks, having heads or other end closures whichare integral with the container body prior to the disposition of theliner therein. Containers of a type having a removable lid, or other endclosure, which would permit the placement of a liner within thecontainer prior to attachment of the lid are excluded from the presentinvention. The interior liner of the closed container of the presentinvention may be of substantially any thermoplastic film, such as nylonor polyamide film, polypropylene resin film, or the like, the particularmaterial depending upon the characteristics of the product to becontained by the container. Similarly, the thickness of the filmemployed depends upon the size of the container, density of the product,strength of the film, etc. The invention is described in detailhereinafter with respect to a closed or integral head drum; however, asnoted above, it is intended that closed containers other than drums bealso embraced by the invention.

Referring to FIGURE 1, there is shown a conventional closed integralhead drum 11 including a cylindrical body 12, integral bottom 13, andintegral head 14. The head is provided with the usual large and smallbung holes 16 and 17 which are internally threaded to receive externallythreaded large and small bungs 18 and 19;

Within the drum 11 there is provided a plastic film bag or liner 21 insubstantial contact with the interior of drum and containing a liquid orother product 22 having a level near the top of the drum. Adjacent thelarge bung hole 16, the liner is provided with an opening which issealably closed as by means of a pinch clamp 23, or the like, withgathers 24 of the liner extending from the clamp. In other instances, aheat seal may be employed to close the opening.

It will be appreciated that by virtue of the liner 21, the product 22does not contact the interior walls of the drum 11. Thus, the productcannot be contaminated by the material of the drum, rust whichfrequently forms thereon, the remnants of other products in the eventthe drum is reused, etc. Furthermore, any cracks, or the like, in thedrum are bridged by the liner such that leakage of the product isprevented.

When it is desired to pour the product 22 from the lined container, thelarge bung 18 is removed and the gathers 24 of the liner are grasped andwithdrawn through the bung hole. The pinch clamp 23, or other sealmeans, is in this manner positioned exteriorly of the drum and is nowaccessible. The clamp is removed or the seal otherwise broken. Aconventional externally threaded pouring spout 26 is inserted into theliner opening and is encompassed by the gathers 24. The spout threadsare engaged with the large bung hole threads through the intermediary ofthe liner material as indicated in FIGURE 2. A seal is thus providedbetween the liner and spout such that the product 22 within the linermay be poured from the spout. During pouring of the product the smallbung 19 may be removed in which case the drum interior is vented toatmosphere and the liner will collapse as the contents are poured.Alternatively, the small bung may be left in place such that a partialvacuum is retained within the drum and the liner will tend to remainadjacent the drum walls during pouring. Subsequent to pouring of theproduct from the drum, the liner may be withdrawn through the large bunghole and disposed of. Another liner may be placed in the drum in 'amanner described hereinafter, and the drum may then be reused.

Considering now a method of positioning the liner 21 within the closeddrum 11 for filling, it is first to be noted that the liner is in theform of a sealed rectangular plastic film bag. For this reason, theliner is thermoplastic such that fluid tight seals may be readily formedduring manufacture by conventional heat sealing techniques. The liner isof a suflicient size to fill the drum upon expanding. In this regard,plastic films are typically quite stretchable such that the liner sizeis not critical. The liner is initially prepared by folding in themanner illustrated in FIGURES 3 to 5. More particularly, the liner isfolded widthwise 'at a plurality of lengthwise extending fold lines 27to form a plurality of accordion pleats 23. In other words, a widthwiseextending stacks of relatively narrow lengthwise pleats are providedwhich are extendible in the widthwise direction. In addition, the pleats28 are folded lengthwise at a plurality of widthwise fold lines 29. Thelengthwise folding is preferably such as to provide a plurality ofwidthwise accordion pleats 31 extendible in the lengthwise direction.However, the lengthwise folding may alternatively be such as to form aflat spiral.

Although the folded liner may be utilized per se in the method, it isfrequently desirable that the folded liner be provided as a pre-wrappedpackage, as shown in FIGURES 4 and 5, to prevent unintentional unfoldingduring handling. In this regard, an encircling wrapper 32 of paper, orthe like, may be placed about the folded liner to retain same in foldedcondition. The wrapper is secured to itself, but not to the liner. It isof importance to note that the wrapper is perforated, or otherwiseformed with a weakened section 33 extending lengthwise thereof,preferably adjacent the outermost lengthwise pleat 28 that is providedwith the liner opening. This opening may be provided by diagonallycutting a corner of the liner from one of the outermost pleats 28, asindicated at 34. If desired, a stiffening ring 36 of paper, or the like,may be secured about the opening.

The folded liner, with or without the wrapper 32, is inserted throughthe large bung hole 16 into the interior of the drum 11, as indicated inFIGURE 6. The liner is oriented with the stack of pleats 28 facingradially inward from the bung hole and from the pleat having the opening34. In other words, the pleats 28 are oriented for widthwise explanationinto the drum interior from the bung hole.

With the folded liner thus positioned within the drum, the liner isinflated. This is preferably accomplished by means of a high volume, lowpressure air source, as indicated at 37, having a tube 38, or the like,inserted in the liner opening 34 and sealed therewith as illustrated inFIGURES 7 and 8. As inflation of the liner oommences, and the linerbegins to expand, the force exerted on the wrapper 32 at the weakenedsection 33 severs the wrap. The wrap thus falls free of the liner intothe drum to permit unfolding and full inflation of the liner. As theliner is inflated, it expands into the drum as shown in FIGURE 8, theair in the drum displaced by the inflating liner being vented toatmosphere through the small bung hole 19. Upon full inflation of theliner, which may be observed through the small bung hole, the liner isin contact with the drum walls. It will be appreciated that infiation ofthe liner may be conducted in various other ways such as by drawing avacuum on the small bung hole either alone or in conjunction with theintroduction of air to the liner.

With the liner fully inflated, the small bung 19 is replaced to retainthe partial vacuum in the drum. The air tube 38 is removed and the lineris filled directly with a product, or is sealed as by means of the clamp23 for subsequent filling. Filling of the liner is accomplished merelyby inserting a filling pipe 39 into the opening 34- and flowing theproduct therethrough, as depicted in FIGURE 9.

When the liner is filled, the portion of the liner extending through thelarge bung hole 16 is gathered (gathers 24) and the pinch clamp 23, orthe like, put in place to seal the product therein. A heat seal may bealternatively employed to seal the liner opening. Thereafter, theexterior end of the liner is urged through the large bung hole 16 andthe large bung 18 is put in place, as indicated in FIGURE 10.

In some instances, such as when the lined drum is not to be filled for arelatively long time after inflation of the liner, there may be atendency for the liner to deflate to some extent and fall away from thehead of the drum.

This also tends to cause the liner to fall away from the walls of thedrum body. These difficulties are readily overcome by slightly modifyingthe method to provide for adhesion of the inflated liner to the interiorsurface of the drum head 14. This may be readily accomplished byapplying a suitable adhesive to the interior head surface and upperportions of the interior surface of the body prior to introduction ofthe liner into the drum and inflation of the liner into contact with thedrum walls. The adhesive may be sprayed upon the interior head surfaceand preferably the upper third of the interior body surface by means ofa reverse spray nozzle 41 inserted through the large bung hole anddirecting a spray 42 of adhesive upwardly upon the interior surfaces ofthe drum head and upper portion of the drum body, as shown in FIGURE 11.After the adhesive has set sufficiently, the folded liner is introducedinto the drum and inflated in the manner previously described. Now,however, when the liner is fully inflated into contact with the drumwalls, the liner adheres to the head and upper portion of the body byvirtue of the previously applied thin' layer 43 of adhesive, asindicated in FIG- URE 12. Thus, even if the liner deflates to someextent prior to filling, the liner is retained in place in contactwithinterior surfaces of the drum head and upper part of the drum bodyto prevent the liner from falling away therefrom.

In conjunction with reuse of a lined drum, or other container, after thecontents are emptied, it is of importance that the old liner be readilyremoved for replacement with a new liner. Removal of the liner from thedrum may be readily accomplished in the manner illustrated in FIGURE 13.Wit-h the liner emptied and detached from the head and upper portions ofthe body, in the event the liner had been adhesively secured thereto, anelongated tube 44 of cardboard, plastic, or the like, is inserted intothe liner opening defined within the externally protruding gathers 24.The tube is urged into the liner to a position adjacent the bottom ofthe drum. The gathers 24, with tube 44 encompassing same and protrudingexternally therefrom, are then grasped and pulled simultaneously fromthe large bung hole. The liner in encountering the portions of the headabout the large bung hole is collapsed, with any air trapped within theportions of the liner inwardly from the large bung hole being ventedthrough the tube 44, as indicated by the arrows in FIGURE 13. In thismanner, the liner is deflated as the liner and tube are withdrawnthrough the large bung hole. Subsequent to removal of the old liner, anew liner may be inserted in the drum in accordance with the methodpreviously described, and the lined drum again filled with a product.

Although the invention has been hereinbe'fore described with particularrespect to a preferred embodiment of the product, and specific steps ofthe method thereof, it will be appreciated that numerous modificationsand changes may be made therein without departing from the true spiritand scope of the invention. For example, some drums are provided withbungs at locations other than in the head. In this regard, a side bungmay be provided in the body of the drum. In the event it is desired toempty the lined drum contents from such a bung hole, the drum may bemanipulated to a position wherein the drum contents are disposed awayfrom the bung hole and the liner in the region thereof is unbulged andhence substantially loose. The loose portion of the liner may then begrasped through the bung hole and withdrawn therethrough. The withdrawnportion may be cut and a spout inserted to facilitate draining of thedrum contents. Thus, it is not intended to limit the invention except bythe terms of the appended claims.

What is claimed is:

1. A method of interiorly lining a closed container having a smallopening in an end thereof comprising folding a flat rectangular plasticfilm sealed bag-like liner to form a plurality of lengthwise accordionpleats, providing an opening in said liner at a corner thereof includedin an exterior one of said pleats, inserting the pleated liner throughsaid opening of said container into the interior thereof with saidopening of said liner disposed exteriorly and said plea-ts disposed tounfold into the con-t ainer, inflating said liner into contact with theinterior walls of said container, and maintaining said liner in inflatedcondition until a product is introduced through the opening thereof.

2. A method according to claim 1, further defined by applying anadhesive to the interior surface of said end of the container having anopening therein and adjacent interior portions of said container priorto said step of inserting the pleated liner through said opening in saidend.

3.1;A method according to claim 1, further defined by placing a wrapperhaving a weakened] section about said pleated liner with the weakenedsection oriented lengthwise of the pleated liner for severing uponinflation thereof.

4. 'A method of containing a product in a drum of the type having abody, an integral bottom, and an integral head provided with large andsmall bung holes receiving large and small bungs comprising the steps offolding a fiat rectangular plastic film sealed bag-like liner along aplurality of lengthwise fold lines to form a plurality of widthwiseunfoldable accordion pleats, folding said liner along at least one foldline widthwise of said pleats, providing an opening in said liner at acorner thereof contained in an exterior one of said lengthwise pleats,removing said large and small bungs from said large and small bungholes, inserting the folded liner through said large bung hole into theinterior of said drum with said opening disposed exteriorly and saidpleats oriented to unfold radially inward into said drum from said.large bung hole, inflating said liner into contact with the interiorsurfaces of said drum, securing said small bung in said small bun-ghole, introducing said product through said opening into said inflatedliner and sealing said opening upon filling of the liner with saidproduct, placing the sealed opening interiorly of said drum through saidlarge bung hole, and securing said large bung in said large bung hole.

5. A method according to claim 4, further defined by said step ofinflating said liner comprising introducing air at a high volume and lowpressure into said opening of said liner.

6. A method according to claim 4, further defined by placing a wrapperhaving a weakened section lengthwise thereof about the folded liner withthe weakened section oriented lengthwise of said pleats prior toinsertion of the folded liner through said large bung hole.

7. A method according to claim 41, further defined by applying adhesiveto the interior surface of said head and upper interior surfaces of saidbody prior to said step of inserting the folded liner.

8. A method of reusing a closed drum to contain a product, said drumbeing of the type having a body, an integral bottom, and an integralhead provided with large and small bung holes receiving large and smallbungs comprising the steps of folding a flat rectangular plastic filmsealed bag-like liner to form a plurality of lengthwise accordionpleats, providing an opening in said liner at a corner thereof includedin an exterior one of said pleats, removing said large and small bungs,inserting the pleated liner through said large bung hole into theinterior of said drum with said opening disposed exteriorly and saidpleats disposed to unfold into the interior of said dr-um, inflating andfilling said liner with a product through said opening, sealing saidliner, securing said bung-s in said bung holes, removing said largebung, unsealing said liner, emptying said product from said liner,insenting an elongated tube into said liner, withdrawing said tube andliner extending thereabout from said drum through said large bung holewith air trapped in the liner being exhausted through said tube, andrepeating all of the foregoing steps.

FOREIGN PATENTS 708,813 5/1954 Great Britain. 350,598 1/ 1961Switzerland, References Cited 3 85,720 3 1965 Switzerland.

UNITED STATES PATENTS WILLIAM W. DYER, 111., Primary Examiner.

Hagoplan 156-294 X Fletcher 22 3 X ROBERT C. R'IORDON, Examiner. Daggitt220-63 X N. ABRAMS, Assistant Examiner, Jones 220-63 X 10 Hoifmann156-287 X

